Why We Stopped Offering Calcium Supplements to Our Breeding Hens

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I’ve raised chickens since 1992. So that’s what?…25 years? Sheesh! Time flies when you’re raising chickens evidently. In those 25 years, I’ve noticed something. A correlation between offering a calcium supplement and difficult hatches.

When I first started raising chickens there was no internet. No chicken forums, no Community Chickens. We didn’t live in a farming community, I didn’t come from farming roots. There wasn’t a whole section of the library or the local bookstore devoted to small scale homesteading, chicken raising or self sustainability. So needless to say, when I brought my first chicks home, I had no idea what I was doing. My dad and I saw chicks for sale while buying bird seed at a hardware store. We bought 6 on impulse and decided we’d wing it.

We fed them cracked corn their entire lives. Just corn, kitchen scraps and whatever they found in the yard…because that’s what we thought chickens ate. Looking back, it amazes me how resilient chickens really are. I wander through the poultry department of our local feed store now and look at all the different feeds, supplements, even toys for chickens and think of those first 6 chickens and their corn diet. I’m not suggesting that this should be how anyone raises chickens today. We’ve learned a lot and now offer our chickens a healthy, well balanced feed. And as a result, our chickens now lay a lot more eggs than those first 6 chickens ever did.

After that first flock I was hooked on chickens. We eventually discovered actually “chicken feed” and cut out the corn and replaced it with crumbles. With this change we noticed a surge in egg production which was quite nice.

A few years later I bought my first incubator and decided to try hatching out a few chickens. It was an amazing experience and since that first spring, hatching and breeding have become my favorite part of chicken keeping.

As my knowledge of chickens grew, I learned that chickens should be fed a calcium supplement for strong eggshells and to prevent our hens from leaching calcium from their bones in order to produce an egg.

I promptly made this supplement addition to our flock’s feeding regimen. Our chickens picked at the calcium slowly over time, and it became a regular part of their diet offered free choice.

Later that summer I decided to hatch out an incubator full of chicks. It ended up being the worst hatch I’d ever experienced. 4 of the 7 chicks pipped, but were unable to zipper the eggshell. I had to assist in the rest of the hatch process and we lost 3 of those 4 chicks within the next day or two.

The rest of the hatches that summer were similar. I blamed it on a humidity issue. And played around with humidity in the incubator. No matter what I did differently, it didn’t really seem to make a difference. The chicks struggled to hatch.

The following spring for whatever reason, laziness, forgetfulness…a little of both. We ran out of oyster shell and never replaced it. I noticed that the chicks I hatched out that year had a much easier time breaking through the eggshell.

And this correlation is something I’ve picked up on over the years. Which makes me wonder how much calcium do chickens really need? In the 25 years of raising chickens we’ve only had maybe 2 or 3 shelless eggs. When one does pop up, it’s quite the phenomenon and usually happens with a young layer who hasn’t quite worked her system out yet.

I don’t have any scientific proof that there is a correlation. I haven’t talked to a veterinarian, and I can’t seem to find any reliable articles on the internet that offer any incite on the issue.

What prompted me to write this article was a question that I got from a lady who follows our blog who was having a hard time with a turkey egg zipping. I asked her about feeding calcium and she agreed with my theory that when she feeds calcium she has difficult hatches. That the shell of the egg seems to be too thick and the chicks can’t break through.

So where am I going with all this?

I’m sure for every person who may have noticed this in their own hatches, there are 10 who feed calcium and have no problems what so ever.

So here’s my conclusion. We no longer offer a calcium supplement to our breeding hens. Especially in the spring when I’m collecting eggs for hatching. Their feed has calcium and I’m of the opinion that this is enough for them to be healthy. If we were to notice a soft shell egg (which we never do) I would be prompted to offer calcium either in the form of oyster shell or dried, crushed eggshells. I’ve also offered calcium in the winter months just for added health because our chickens aren’t free ranging at this time.

I also feel that if you don’t plan on hatching out eggs that a calcium supplement can’t hurt and is probably a healthy choice for your flock. In fact I recommend it. If you don’t have to worry about difficult hatches, you may as well offer this nutrient.

But if you have had problems with hatches and can’t crack the code with adjustments to humidity, etc. (which can be so frustrating) perhaps this might help you. It’s at least something to consider.

What I’m really interested in is if any of you have also noticed this with your own hatches? Do you notice that oyster shell works better than crushed eggshells and vice versa? I’d also be interested in what supplements you feed your chickens and why. I’d like to do a follow up post on this subject after you all weigh in. Hopefully together as a community we can help each other. Especially with the most delicate and miraculous part of chicken keeping.

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5 Comments

We hatched chicks again this year the old fashioned way, under broody hens. 2 chicks had a difficult time zipping the shells. One finally managed but was born spraddle legged and eventually died. The other needed a little assistance, seemed to be ok but died the next day. We had oyster shells on demand for the hens during the egg producing time. Last year we did not and had no problems. Coincidence? Not enough evidence to know.

I’ve sold 54 batches of hatching eggs in the last year, and if folks know what they are doing and have adequate incubators (or pay a person I recommend to incubate for them) their hatch rate is very high. I ask for reports and most say they hatch almost every egg. I usually offer calcium about once a month, and it is gone (either eaten or scattered from the metal feeder I hang on a wall) in a week (no more than two cups), for seven hens. I’ve never noticed whether my two roosters are interested in it. My flock is mostly contained, and allowed to ‘free range’ over about a half acre of varied forage. They get a complete layer or ‘all flock’ higher protein feed depending on whether I have a broody with chicks, a lot of kitchen and garden waste, and a cup of scratch grains every day or so. My birds are 100% Icelandic chickens, a medium-sized thrifty landrace that lays a lot of eggs.

I offer my chickens crushed oyster shell, calcium carbonate (crushed, and available in 50 lb bags), free choice, as well as drying their egg shells, crushing them and adding them to their morning porridge. I’ve not had any problems with hatches in my incubator or under a broody hen. I figure the chickens will take what they need and ignore the rest.

Occasionally we will. There is already corn in their manufactured feed. Corn has very little nutritional value so when you feed it in addition to a balanced feed you are essentially diluting their nutrition. Corn can be used to fatten chickens up as it is high in carbohydrates and packs on calories quickly. It really won’t hurt to feed corn in addition to feed, but for maximum egg production, I’ve found that a balanced feed works best for us. 🙂